If you’ve used Facebook’s share functionality on an external website, you have probably by now figured out that whenever the first time Facebook visited a page (most probably when someone shared your URL on Facebook), it generates a cache of the preview image(s), the title and the description copy.
Facebook caches the most recently shared and already shared posts/links for a better performance. This causes issues at time when we update the title, picture being shared or the description of the page because Facebook still shows the older version of the page.
Once you have fixed what was causing the preview to pull in incorrectly on your website, you will need to clear Facebook’s cache so it knows to pull in the new data.
Any link can be used here and on clicking Debug it will fetch the latest title, description, image and other details. By using an already shared link here in this tool, Facebook returns the latest content and at the same time updates its cache with the latest content.
Copy and paste the URL you are refreshing into the box and click “Debug.” The tool will show you diagnostics on the URL that you can ignore. Facebook should now pull in the updated data.